Signatures of the Israel Junction II: Double Photon Rings in Slowly Rotating Kerr Spacetime with Thin Shell

Abstract

Applying the junction conditions to the slowly rotating Kerr spacetime with a thin shell, when higher order terms in the spin parameter a can be neglected, we find that while the angular momentum $L$ and Carter constant $C$ of the ray remain unchanged upon crossing the shell, its energy $E$ does not. Consequently, the impact parameters $\eta =L/E$ and $\xi =C/E^2$ of the ray are discontinued at the shell. Utilizing this transformation, we study the shadow of this spacetime and the corresponding images from an equatorial thin accretion disk. The presence of the shell gives rise to distinctive features in the observed images. Notably, we observe distinct double photon rings in the images, which can gradually merge into a single ring. Moreover, the shadow boundaries and the photon rings do not exhibit a one-to-one correspondence. The abrupt changes in redshift factor and the truncated photon regions profoundly influence the image, producing distinctive features such as the step-like structures. These features in shell-equipped spacetimes can help evaluate, through future astronomical observations, the applicability of the Israel junction condition and the shell model in real astrophysical systems.

arXiv comment26 pages, 8 figures; published version

References in corpus (40)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• Gravitational Vacuum Condensate Stars
• Dark matter annihilation at the galactic center
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• Testing the rotational nature of the supermassive object M87* from the circularity and size of its first image
• Generating rotating regular black hole solutions without complexification
• The Current Ability to Test Theories of Gravity with Black Hole Shadows
• Shadows of spherically symmetric black holes and naked singularities
• A new probe of dark matter properties: gravitational waves from an intermediate mass black hole embedded in a dark matter mini-spike
• Quantum Phase Transitions and the Breakdown of Classical General Relativity
• Image of Kerr-Melvin black hole with thin accretion disk
• Influence of Quantum Correction on the Black Hole Shadows, Photon Rings and Lensing Rings
• Photon Ring and Observational Appearance of a Hairy Black Hole
• Shadows of boson and Proca stars with thin accretion disks
• Photon Spheres and Spherical Accretion Image of a Hairy Black Hole
• Can we distinguish black holes from naked singularities by the images of their accretion disks?
• On the shadow of rotating traversable wormholes
• Shadows and photon rings of regular black holes and geonic horizonless compact objects
• Novel shadows from the asymmetric thin-shell wormhole
• Observational signatures of strongly naked singularities: image of the thin accretion disk
• Event Horizon Telescope observations exclude compact objects in baseline mimetic gravity
• Images from disk and spherical accretions of hairy Schwarzschild black holes
• Light Ring behind Wormhole Throat: Geodesics, Images and Shadows
• Black Holes with Multiple Photon Spheres
• New light rings from multiple critical curves as observational signatures of black hole mimickers
• Linearization stability of reflection-asymmetric thin-shell wormholes with double shadows
• The effect of scalar hair on the charged black hole with the images from accretions disk
• Optical appearance of a thin-shell wormhole with a Hayward profile
• Cuspy and fractured black hole shadows in a toy model with axisymmetry
• Observational properties of hot-spots orbiting relativistic fluid spheres
• The future ability to test theories of gravity with black-hole shadows
• Is a photon ring invariably a closed structure?
• Dark Matter at the Galactic Center
• Investigating the shadows of new regular black holes with a Minkowski core: Effects of spherical accretion and core type differences
• Some optical properties of rotating wormhole in Bopp-Podolsky electrodynamics
• Counter-rotating Kerr manifolds separated by a fluid shell
• Matching slowly rotating spacetimes split by dynamic thin shells
• Image of the time-dependent black hole
• Shadow formation in gravitational collapse: Redshift and blueshift by spacetime dynamics